The Active Clamp Forward Circuit Study

The dissertation analyzed several topologies, which are commonly used in the Brick DC/DC converters. And it mainly focuses on analyzing the active clamp forward converter.The active clamp forward is a very suitable topology for Brick DC/DC. This topology has many advantages such as following: Duty cycles beyond 50% max are obtainable, which is very suitable for wide input range situation just like Brick DC/DC. It can provide complete square wave in the transformer, which can provide a simple self-driving method for synchronous rectifier.Detail operation principle, design equations and loss estimation for such a topology are presented. And the small signal model of this topology is presented in this paper too. The large-signal transient of this topology is also analyzed.The experiment results, obtained from a 12V30A-140kHz prototype, valifie the theoretical analysis of this topology.